Thanks for the suggestions.
Yes, I am using the correct subsystem.
Good idea, I will check the attitude angles.
I know I checked the CG on pitch but I probably didn't on the roll axis.
By the way, I am using the 4.0_beta branch. Appending my config at the end just in case it's useful (or of interest).
<!-- XAircraft X650 frame equiped with Lisa/M using the X650's UltraPWM ESCs -->
<airframe name="lisa_x650">
<firmware name="rotorcraft">
<target name="ap" board="lisa_m_1.0">
<subsystem name="radio_control" type="spektrum"/>
<subsystem name="actuators" type="pwm_supervision"/>
<subsystem name="telemetry" type="transparent"/>
<define name="SERVO_HZ" value="500"/>
<define name="RADIO_MODE" value="RADIO_AUX1"/>
<define name="RADIO_KILL_SWITCH" value="RADIO_GEAR"/>
<define name="RADIO_CONTROL_SPEKTRUM_SIGNS" value="\{1,1,-1,1,1,-1,1,1,1,1,1,1\}"/>
</target>
<target name="sim" board="pc">
<subsystem name="fdm" type="nps"/>
<subsystem name="radio_control" type="ppm"/>
<subsystem name="actuators" type="mkk"/>
</target>
<subsystem name="imu" type="aspirin_v1.5"/>
<subsystem name="gps" type="ublox"/>
<subsystem name="stabilization" type="euler"/>
<subsystem name="ahrs" type="int_cmpl_quat"/>
</firmware>
<servos min="0" neutral="0" max="0xff">
<servo name="FRONT" no="0" min="200" neutral="200" max="1200"/>
<servo name="BACK" no="1" min="200" neutral="200" max="1200"/>
<servo name="LEFT" no="2" min="200" neutral="200" max="1200"/>
<servo name="RIGHT" no="3" min="200" neutral="200" max="1200"/>
</servos>
<commands>
<axis name="PITCH" failsafe_value="0"/>
<axis name="ROLL" failsafe_value="0"/>
<axis name="YAW" failsafe_value="0"/>
<axis name="THRUST" failsafe_value="0"/>
</commands>
<command_laws>
<set servo="FRONT" value="0"/>
<set servo="BACK" value="1"/>
<set servo="LEFT" value="2"/>
<set servo="RIGHT" value="3"/>
</command_laws>
<!-- for the sim -->
<section name="ACTUATORS_MKK" prefix="ACTUATORS_MKK_">
<define name="NB" value="4"/>
<define name="ADDR" value="{ 0x52, 0x54, 0x56, 0x58 }"/>
</section>
<section name="SUPERVISION" prefix="SUPERVISION_">
<define name="STOP_MOTOR" value="100"/>
<define name="MIN_MOTOR" value="190"/>
<define name="MAX_MOTOR" value="650"/>
<define name="TRIM_A" value="0"/>
<define name="TRIM_E" value="0"/>
<define name="TRIM_R" value="0"/>
<define name="NB_MOTOR" value="4"/>
<define name="SCALE" value="256"/>
<define name="ROLL_COEF" value="{ 0 , 0, 256, -256 }"/>
<define name="PITCH_COEF" value="{ 256, -256, 0, 0 }"/>
<define name="YAW_COEF" value="{ 256, 256, -256, -256 }"/>
<define name="THRUST_COEF" value="{ 256, 256, 256, 256 }"/>
</section>
<section name="IMU" prefix="IMU_">
<define name="GYRO_P_NEUTRAL" value="7"/>
<define name="GYRO_Q_NEUTRAL" value="-38"/>
<define name="GYRO_R_NEUTRAL" value="-30"/>
<define name="GYRO_P_SENS" value="4.412" integer="16"/>
<define name="GYRO_Q_SENS" value="4.412" integer="16"/>
<define name="GYRO_R_SENS" value="4.412" integer="16"/>
<define name="GYRO_PQ_SENS" value="0.0" integer="16"/>
<define name="GYRO_PR_SENS" value="0.0" integer="16"/>
<define name="GYRO_QR_SENS" value="0.0" integer="16"/>
<define name="ACCEL_X_NEUTRAL" value="5"/>
<define name="ACCEL_Y_NEUTRAL" value="6"/>
<define name="ACCEL_Z_NEUTRAL" value="-5"/>
<define name="ACCEL_X_SENS" value="38.1959737384" integer="16"/>
<define name="ACCEL_Y_SENS" value="38.0891238811" integer="16"/>
<define name="ACCEL_Z_SENS" value="39.6400573777" integer="16"/>
<define name="ACCEL_XY_SENS" value="0.0" integer="16"/>
<define name="ACCEL_XZ_SENS" value="0.0" integer="16"/>
<define name="ACCEL_YZ_SENS" value="0.0" integer="16"/>
<define name="MAG_X_NEUTRAL" value="69"/>
<define name="MAG_Y_NEUTRAL" value="68"/>
<define name="MAG_Z_NEUTRAL" value="-228"/>
<define name="MAG_X_SENS" value="4.10513850603" integer="16"/>
<define name="MAG_Y_SENS" value="4.85423271885" integer="16"/>
<define name="MAG_Z_SENS" value="4.50518931605" integer="16"/>
<define name="MAG_XY_SENS" value="0.0" integer="16"/>
<define name="MAG_XZ_SENS" value="0.0" integer="16"/>
<define name="MAG_YZ_SENS" value="0.0" integer="16"/>
<define name="BODY_TO_IMU_PHI" value="RadOfDeg( 2. )"/>
<define name="BODY_TO_IMU_THETA" value="RadOfDeg( 0. )"/>
<define name="BODY_TO_IMU_PSI" value="RadOfDeg( 0. )"/>
</section>
<section name="AUTOPILOT">
<define name="MODE_MANUAL" value="AP_MODE_ATTITUDE_DIRECT"/>
<define name="MODE_AUTO1" value="AP_MODE_ATTITUDE_DIRECT"/>
<define name="MODE_AUTO2" value="AP_MODE_ATTITUDE_DIRECT"/>
</section>
<section name="BAT">
<define name="CATASTROPHIC_BAT_LEVEL" value="9.3" unit="V"/>
</section>
<section name="STABILIZATION_RATE" prefix="STABILIZATION_RATE_">
<define name="SP_MAX_P" value="10000"/>
<define name="SP_MAX_Q" value="10000"/>
<define name="SP_MAX_R" value="10000"/>
<define name="GAIN_P" value="400"/>
<define name="GAIN_Q" value="400"/>
<define name="GAIN_R" value="350"/>
</section>
<section name="STABILIZATION_ATTITUDE" prefix="STABILIZATION_ATTITUDE_">
<!-- setpoints -->
<define name="SP_MAX_PHI" value="RadOfDeg(45.)"/>
<define name="SP_MAX_THETA" value="RadOfDeg(45.)"/>
<define name="SP_MAX_R" value="RadOfDeg(90.)"/>
<define name="DEADBAND_R" value="250"/>
<!-- reference -->
<define name="REF_OMEGA_P" value="RadOfDeg(800)"/>
<define name="REF_ZETA_P" value="0.85"/>
<define name="REF_MAX_P" value="RadOfDeg(400.)"/>
<define name="REF_MAX_PDOT" value="RadOfDeg(8000.)"/>
<define name="REF_OMEGA_Q" value="RadOfDeg(800)"/>
<define name="REF_ZETA_Q" value="0.85"/>
<define name="REF_MAX_Q" value="RadOfDeg(400.)"/>
<define name="REF_MAX_QDOT" value="RadOfDeg(8000.)"/>
<define name="REF_OMEGA_R" value="RadOfDeg(500)"/>
<define name="REF_ZETA_R" value="0.85"/>
<define name="REF_MAX_R" value="RadOfDeg(180.)"/>
<define name="REF_MAX_RDOT" value="RadOfDeg(1800.)"/>
<!-- feedback -->
<define name="PHI_PGAIN" value="550"/>
<define name="PHI_DGAIN" value="550"/>
<define name="PHI_IGAIN" value="100"/>
<define name="THETA_PGAIN" value="550"/>
<define name="THETA_DGAIN" value="550"/>
<define name="THETA_IGAIN" value="100"/>
<define name="PSI_PGAIN" value="380"/>
<define name="PSI_DGAIN" value="320"/>
<define name="PSI_IGAIN" value="75"/>
<!-- feedforward -->
<define name="PHI_DDGAIN" value=" 300"/>
<define name="THETA_DDGAIN" value=" 300"/>
<define name="PSI_DDGAIN" value=" 300"/>
</section>
<section name="INS" prefix="INS_">
<define name="BARO_SENS" value="3.3" integer="16"/>
</section>
<section name="GUIDANCE_V" prefix="GUIDANCE_V_">
<define name="MIN_ERR_Z" value="POS_BFP_OF_REAL(-10.)"/>
<define name="MAX_ERR_Z" value="POS_BFP_OF_REAL( 10.)"/>
<define name="MIN_ERR_ZD" value="SPEED_BFP_OF_REAL(-10.)"/>
<define name="MAX_ERR_ZD" value="SPEED_BFP_OF_REAL( 10.)"/>
<define name="MAX_SUM_ERR" value="2000000"/>
<define name="HOVER_KP" value="150"/>
<define name="HOVER_KD" value="80"/>
<define name="HOVER_KI" value="20"/>
<!-- 1.5m/s for full stick : BOOZ_SPEED_I_OF_F(1.5) / (MAX_PPRZ/2) -->
<define name="RC_CLIMB_COEF" value ="163"/>
<!-- BOOZ_SPEED_I_OF_F(1.5) * 20% -->
<define name="RC_CLIMB_DEAD_BAND" value ="160000"/>
<define name="INV_M" value ="0.21"/>
</section>
<section name="AHRS" prefix="AHRS_">
<define name="PROPAGATE_FREQUENCY" value="512"/>
<!-- Magnetic field values: Aarau -->
<define name="H_X" value=" 0.4497397"/>
<define name="H_Y" value=" 0.0110889"/>
<define name="H_Z" value=" 0.8930908"/>
</section>
<section name="GUIDANCE_H" prefix="GUIDANCE_H_">
<define name="PGAIN" value="100"/>
<define name="DGAIN" value="100"/>
<define name="IGAIN" value="0"/>
</section>
<section name="MISC">
<define name="FACE_REINJ_1" value="1024"/>
</section>
<section name="SIMULATOR" prefix="NPS_">
<define name="ACTUATOR_NAMES" value="{"front_motor", "back_motor", "right_motor", "left_motor"}"/>
<define name="INITIAL_CONDITITONS" value=""reset00""/>
<define name="SENSORS_PARAMS" value=""nps_sensors_params_booz2_a1.h""/>
</section>
<firmware name="lisa_m_test_progs">
<target name="test_led" board="lisa_m_1.0"/>
<target name="test_uart_lisam" board="lisa_m_1.0"/>
<target name="test_servos" board="lisa_m_1.0"/>
<target name="test_telemetry" board="lisa_m_1.0"/>
<target name="test_imu_aspirin" board="lisa_m_1.0"/>
<target name="test_rc_spektrum" board="lisa_m_1.0"/>
<target name="test_baro" board="lisa_m_1.0"/>
</firmware>
</airframe>